Step 1

Combine the raspberries, sugar, lemon rind, lemon juice and tartaric acid in a large saucepan over medium heat. Cook, stirring, for 5 mins or until sugar dissolves. Strain through a fine sieve into a bowl. Use the back of a spoon to push as much pulp through as possible. Return to a clean saucepan. Place over high heat and bring to the boil. Cook for 2 mins or until syrup thickens slightly.

Step 2

Carefully pour into a sterilised bottle and seal. Place in the fridge to chill.

Step 3

Pour cordial into serving glasses and top with mineral water and ice to serve.